Production of heterocyclic dithiophosphoric esters



United States Patent Ofiice a 2,841,605 Patented July 19 58 PRODUCTION OF I-IETEROCYCLIC DITHIOPHOSPHORIC ESTERS William M. Lanham, Charleston, W. Va., assignor to Union Carbide Corporation, a corporation of New York No Drawing. Application January 12, 1955 Serial No. 481,495 13 Claims. Cl. 260-461) u where in R, R R R R and R respectively; designates a radical of the class consisting of hydrogen and the alkyl radicals; m=0 or 1; Z designates a member of the class consisting of O was I r and CN radicals wherein R designates a radical of the class consisting of hydrogen, the saturated and olefinically unsaturated aliphatic hydrocarbon radicals, the aromatic monocyclic hydrocarbon radicals, and the corresponding halogen-substituted aliphatic and aromatic hydrocarbon radicals; and n is 0 or 1.

The novel compounds of this invention are useful as pesticides. Certain of the compounds have proven effective in aqueous suspensions for the control of bean aphids, and red spider mites and Mexican beetle larvae. The compounds also have potential utility as plasticizers for synthetic resins, and as corrosion inhibitors, flotation agents and petroleum additives.

halogen-substituted alphatic and aromatic radicals.

The reaction can be conducted in the presence of a small amount of a suitable condensation catalyst, suchas the aliphatic tertiary amines, e. g., triethylamine; and the alkali metal hydroxides and carbonates. However, the use of a catalyst is not necessary.

When the unsaturated ester starting material is highly reactive, a polymerization inhibitor such as hydroquinone preferably is present in the reaction mixture.

It is generally preferred to conductthe reactionin the presence of an inert solvent, particularly where one or both of the reactants are solids. Useful inertso lvents include saturated esters of fatty acids, such as ethyl acetate, amyl acetate, 2-ethylhexyl acetate, methyl propionate, and methyl and ethyl butyrates; ketones such as acetone and methyl isobutyl ketone; ethers such'as' dioxane; aromatic compounds such as benzene, toluene, the xylenes, chlorobenzene and nitrobenzene; carbon tetrachloride; chloroform; trialkyl phosphates such as triethyl and.tri-(2-ethylhexyl)phosphates; and saturated nitriles such as acetonitrile and propionitrile.

' The reaction can be conducted at temperatures within the range from -20 C. to about 150 C., btu temperatures ranging from around 25 C. to about 100 C. are preferred inithe interest of good yields of product. Preferably the unsaturated carboxylic ester, which may contain a polymerization inhibitor, is added slowly in small successive amounts to a solution of the phosphorushydrocarboncontaining reactant in an inert solventof the type de-- a scribed until approximately equimolar portions have reacted, as illustrated by the equation O o ssomornodm P I where G represents a hydrocarbon radical of the formula CRR (CR R )nCR R wherein R, R R R R and action mixture is'first washed'with a dilute solution of sodium bicarbonate or the equivalent, washed with water,

The novel compounds can be produced by reacting a where in R, R R R R and R respectively, designates and the washed product stripped of unreactedmaterials and solvent by distillation under high vacuum. The desired product is recovered in good purity as a still residue.

The heterocyclicdithiophosphoric acidsused as start-- ing materials can be made by reacting phosphorus pentasulfide With an alkane -1,2-diol or an al kane-l,3-diol at temperatures within the range from 25 C. to 100 C.

and above, preferably in the presence of an inert solvent for the diol and reaction products, and removing the byproduct hydrogen sulfide ,as formed. Such a process is a radical of the class consisting'of hydrogen and the alkyl groups, and m is 0 or 1, with an ester of the fromula CH =CH(CH nZ, wherein n is 0 or 1, and Z isa radical of the class consisting of CN and the a described in my pending applicatiomserial No. 387064, filed October-19; 1953.' a

Among heterocyclic dithiophosphoric acids useful in the process may bementioned: 2 5 mrcapto-Z thiono- 1,3,2,-dioxaphosphorinane, and the 4-ethyl-, 4'-bu tyl-, 4- (2-ethy1hexyl)-, 4-tetradecyl-, 5-ethyl-, 5-buty1-, 5-decyl-, 5-heptadecyl-, 4,5-diethyl-, 4-methyl-5-ethyl-, 4,5-dibutyl-, 4-propyl-,5-tetradecyl-, 5-ethyl-5-butyl-, 5,5-dibutyl-, 5- butyl- 5 dodecyl-, 4,4,6-trimethyl-, and 4,4,5,5-tetramethyl-substituted 2 mercapto 2 thiono -.1,3,2-dioxaphosphorinanes; and the corresponding substituted and unsubstituted 2 mercapto 7 2 thiono 1,3,2 dioxaphospholanes.

Among unsaturated esters of hydrocyanic acid and of monocarboxylic acids of the formula R COOH useful in the process may be mentioned the vinyl and allyl esters of hydrocyanic acid, and corresponding esters of fatty acids such as formic, acetic propionic, butyric, caproic, 2-ethylhexanoic, capric, and stearic acids; halogen-substituted fatty acids such as the chloroand bromo-acetic, propionic and butyric acids; oleic acid; benzoic acid; and the mand-p-chloro-substituted and o-, mand p-alkyl-substituted benzoic acids.

The following examples .will serve to illustrate the invention.

' Example 1 To an agitated solution of 68 grams (0.3 mol) of 5,5- diethyl-2-mercapto2-thiono-1,3,2-dioxaphosphorinane in 200 grams of toluene there were added dropwise during 20 minutes 86 grams (1 mol) of vinyl acetate, while maintaining the reaction temperature of 4045 C. After heating atthis temperature for 2.5 additional hours, and then at 2 C, for about 16 hours, the reaction mixture was stripped by distillation to a kettle temperature of 70" C. under less than 4 mm. of mercury pressure. There was thus obtained a 95% yield of 2-(2-acetoxyethylmercapto)-5,5-diethyl 2 thiono 1,3,2 dioxaphosphorinane as a brown solid residue having the following properties: acidity:0.05 cc. of 1 normal KOH/g.; 21 =l .5220. Analysis, percent by weight: percent S:20.6 (theory:20.52); percent P:l0.42; (theory: 992); percent C:40.25 (theory:42.28); percent H:6.:5 0 (theory:6.94).

Hr-O Example 2 To 72 grams (0.3 mol) of 5-ethyl-2-mercapto-4-propyl- 2-thiono-1,3,2-dioxaphosphorinane there were added during minutes dropwise v86 grams (1 mol) of vinyl acetate, while maintaining the kettle temperature at 42 -45 C. .After heating the reaction mixture at 4250 C. for 5 additional hours, it was stripped by distillation to a kettle temperature of 70 C. under less than 4 mm. of mercury pressure. The resultant 2-(2-acetoxyethylmercapto) 5 ethyl 4 propyl 2 thiono 1,3,2 dioxaphosphorinane was secured in 95% yield, based upon the phosphorus-containing reactant, in the form of a fluid residue having the following properties: acidity:0.07 cc. of normal KOH/g; 11 :1.5l20; molecular weight (ebullioscopic):323.5 (theory:326.4). Analysis, percent byweight: percent P:9.53 (theory:9.49); percent S: 19.80 (theory=l9.64); percent C:44.57 (theory:44.l.6) percent H:7.l9 (theory:7.l0).

' .CHa-O S H Cam-CH P-SCHzCHnO C CHa CH-O Example 3 With agitation 86 grams (1 mol)' of vinyl acetate were added dropwise to a solution of 64 grams (0.3 mol) of Z-mercaptoe2-thiono-4,4,6-trimethyl-1,3,2 dioxaphosphorinane in 100 grams of toluene, with heating to maintain a reaction temperature of 4245 C. during the addition and for an additional 5 hours. The reaction mixture then was neutralized with a dilute aqueous sodium bicarbonate solution, washed with water until neutral toward litmus paper, and stripped by distillation to a kettle tem perature of 100? C. under less than 4 mm. of mercury pressure. The resultant 2-(Z-acetoxyethylmercapto)-2- thiono-4,4,6-trimethyl-l,3,2-dioxaphosphorinane was obtained as a yellow liquid residue having the following I weight:

properties: acidity:0.05 cc. of normal KOH/g.; n =1.5239. Analysis, percent by weight: percent 8:22.40 (theory:2l.49); percent P=10.68 (theory:l0.38); percent C:40.02 (theory=40.24); percent H:6.70 (theory:6.42)

H0 8 H on, %SCHlCHIO c on:

C CH:

Example 4 To an agitated suspension of 45 grams (0.2 mol) of 5,5 diethyl 2 mercapto 2 thiono 1,3,2 dioxaphosphorinane in 150 grams of toluene maintained at 25 C. there were added during 8 minutes 24 grams (0.2 mol) of vinyl chloroacetate inhibited with 0.02 'gram of hydroquinone. The agitation was continued at 25 C. for 2.25 hours; after which it was heated at ground 45 50 C. for a .total of 19 hours, and allowed to stand for 4 days at 25 C., .after which it was neutralized with a concentrated aqueous solution of sodium bicarbonate, washed with water until neutral to litmus and stripped by distillation to a kettle temperature of C. under less than 2 mm. of mercury pressure. The resultant 2-(2- chloroacetoxyethylmercapto)-5,5-diethyl-2-thiono 1,3 ,2- dioxaphosphorinane was recovered as a light brown fluid residue having the following properties: n =1.5314. Analysis, percent by weight: percent P:9.26 (theory:8.94); percent C:38.38 (theory:38.l0); percent H:5.91 (theory=5.82); percent 8:19.50 (theory:l8.50; percent Cl:9.73 (theory=l0.22).

02H: CHz-O Example 5 To an agitated suspension .of 45 grams (0.2 mol) of the phosphorus-containing starting material recited in Example 4 in 15.0 grams of toluene, there were added dropwise 62 grams (0.2 mol) of vinyl oleate inhibited with 0.06 gram of hydroquinone,.while maintaining the mixture at 25 C. The mixture then was agitated at 25 C. for 2.25 hours, was heated at 50 C. for 2%. hours, and allowed to stand at 25 C. for 8 days. The mixture then Was neutralized with concentrated aqueous sodium bicarbonate solution, washed with Water until neutral to litmus and stripped ,by distillation to a kettle temperature of 100 C. underless than 2mm. of mercury. The .resultant 5,5 diethyl 2 .(2 oleoyloxyethylmercapto)- 2-thiono-l,3,2-dioxaphosphorinane was obtained as a brown liquid residue having the following properties: acidity:0.25 cc. of 1 normal'KOH/g; salt=0.007 cc. of l N HClO /gram; n =l.4970. Analysis, percent by percent P:5.8.7 (theory=5.79); percent C:60.80 (theory:60.63); percent H =9.70 (theory :9.61); percent S:l2.l (theor'yi:ll.98).

02H, CHE-O *s I 0 Iii'SCHzCHzO C H3: (12H; GHz-O i Example 6 To an agitated suspension of 0.2 mol of 5,5-.diethy1- 2-mercapto-2-thiono-l,3,2edioxaphosphorinane in grams of toluene held at 25 C. there were added dropwise 0.2 mol of vinyl 2-ethylhexanoate, inhibited with 0.03 gram of hydroquinone. The reaction mixture, after heating at 50 C. for 2.5 hours and holding at 25 C.for about 4.5 days was neutralized with a concentrated aqueous solution of sodium bicarbonate, diluted with 100 cc. of ethyl ether, washed with :water until neutral to litmus, and stripped by distillation to a kettle temperature of 100 C. under less than 2 mm. of mercury pressure. The resultant 5,5 diethyl 2 (2 ethylhexanoyloxyethylmercapto) 2 thiono 1,3,2 dioxaphosphorinane was a brown liquid residue having the following properties: acidity=0.06 cc. of 1 normal KOH/g.; n =1.5033. Analysis, percent by weight: percent P=8.l9; percent S=15.15; percent C=51.0; percent H=8.29.

To an agitated suspension in 150 grams oftoluene of 0.2 mol of the phosphorus-containing reactant recited in Example 6 and 0.06 gram of hydroquinone held at 25 C. there were added slowly during 20 minutes 0.2 mol of vinyl stearate. The reaction mixture was allowed to stand at 25 for 45.5 hours, heated at 50 C. for 2.5 hours, and allowed to stand at 25 C. for a total of around" 64 hours. The mixture was neutralized with a concentrated aqueous solution of sodium bicarbonate, washed with water until neutral to litmus, and stripped by distillation to a kettle temperature of 100 C. under less than 2 mm. of mercury. The resultant 5,5-diethyl-2-(Z-octadecanoyloxyethylmercapto) 2 thiono 1,3,2 dioxaphosphorinane was obtained as a brown liquid residue having the following properties: acidity=0.04 cc. of normal KOH/g.; salt=0.02 cc. of N HClO /g.; n =1.4911. Analysis, percent by weight: percent P=5.'88 (theory =5.77); percent C=60..14 (theory=60.41); percent H =9.84 (theory=9.95) percent 8:11.50 (theory=1l.94);

percent yield=7 9.

. Example 8 To an agitated suspension of 0.2 mol of 5,5-diethyl-2- mercapto-2-thiono-1,3,2edioxaphosphorinane in 150 grams of toluene held at 25 C. there were added dropwise 0.2 mol of vinyl benzoate inhibited with 0.03 gram of hydroquinone. After heating at 50 C. for 2.5 hours and holding at 25 C. for a total of about 114 hours, the reaction mixture was washed with concentrated aqueous sodium bicarbonate, diluted with 100 cc. of ethyl ether, washed with water until neutral to litmus, and stripped by distillation to a kettle temperature of 100 C. under less than 2 mm. of mercury pressure. The resultant 2-(2-benzoyloxyethylmercapto)-5,5-diethyl-2-thiono- 1,3,2-dioxaphosphorinane was recovered as a viscous liquid residue having the following properties: acidity =0.03' cc. of normal KOH/g.; salt=0.02 cc. of normal HClO /g.; n =1.5595. Analysis, percent by weight: percent P=8.60 (theory=8 .27); percent C=51.33 (theory=51.35); percent H=6.25 (theory=6.l9; percent S=17.10 (theory=l7.13); percent yield=92.

C211 CHI-'0 s o 7 \O somomo otm During minutes, 53 grams (1 mol) of acrylonitrile were added dropwise to 48 grams (0.28 mol) of 2-mercapto 4 methyl 2 thiono 1,3,2 dioxaphospholane held at 42-50 C. After holdin the reaction mixture at 25 C. for a total of 50 hours, the reaction mixture was stripped by distillation to a kettle temperature of 70 C. under less than 3 mm. of mercury. The resultant 2 (2 cyanoethylmercapto) 4 methyl 2 thiono- 1,3,2-dioxaphospholane was secured as a brown liquid residue having the following properties: acidity=0.12 cc. of normal KOH/g.; n =1.5528. Analysis, percent by weight: percent P=13.88; percent S=26.9; percent N.= 5.64;'percent C=3l.80; percent H=4.'51'..A'97':' percent yield was secured, based uponTth'e phosphoruscontaining reactant.

CHz-O s V P-SOHz-CHs-CN Example 10 Following the general procedure describedin Example 9, the reaction of one mol of acrylonitrile with'0.3 mol' of S-ethyl-Z-mercapto-4-propyl-2-thiono-1,3,2-dioxaphosphorinane gave an 87% yield of 2-(2-cyanoethylme'rproperties: acidity=0.06 cc.

To an agitated solution of 0.3 mol of 2-mercapto 2- thiono 4,4,6 trimethyl 1,3,2 dioxaphosphorinane in 100 grams of toluene there were added dropwise during The reaction mixture thenstood'at 25 C. for 16 hours, and then was heated for 30. minutes at -5 0 C., and thereafter, stripped by distillation.

to a kettle temperature of 100 C. under less than 2 mm. of mercury pressure. The resultant residue was dissolved in 100 cc. of toluene, neutralized with dilute aqueous sodium bicarbonate, washed with water, and stripped by distillation to a kettle temperature of 100 C. under less than 3 mm. of mercury. The resultant 2-(2-cyanoethylmercapto) 2 thiono -4,4,6' trimethyl 1,3,2 dioxaphosphorinane was obtained as a red viscous liquid having the following properties: acidity=0.20 cc. of normal.

'Ihe'invention hereindescribe'd is susceptible ofmodi-Y fication within the scope of thelappended claims. I claim:

1. As new compounds, heterocyclic phosphorus-containing esters having structures corresponding to the] formula wherein R, R R R R and R respectively, designates a radical of the class consisting of hydrogen .and the;

alkyl radicals; m is an integer from 0 to 1; Z designates a member of the class consisting of u a '-o CR and CN radicals wherein R represents a radical of the 7 class consistingof hydrogen, the 'saturatedzaliphatiohydrocarborb radicals; the monocyclic; aromatic. hydrocarbon radicals, and the corresponding halogen-substituted aliphatic and aromatic hydrocarbon radicals, and the -(CHZ)7CH=CHC3 H17 radical; and n is an integer from to 1.

2. As new compounds, 2-(Z-acetoxyethylrnercapto)-2- thiono derivatives of 1 ,3;2.-dioxaphosphorinanes having atleas't onealkyl radical attached, to at least one carbon atom ofithe', dioxaphosphorinanering, the other ring carbon atomshaving 1 to 2 hydrogen atoms attached thereto.

3. As-v new compounds, 2-(2?cyanoethylmercapto) -2- thiono. derivatives of 1,3,2-dioxaphosphorinanes having at least one alkyl radical attached to. at least one carbon atom. of the dioxaphosphorinane ring, the other ring carbon atoms having 1- to 2' hydrogen atoms attachedthereto.

.4.,.As a. new compound, 2-(2-cyanoethylmercapto)-5- ethyl-4rpropyll-2-thiono-1,3,2 dioiraphosphorinane.

51 As, new compounds, 2-(j2'-cyanoethylmercapto)-2- thiono derivatives of a 1,3,2-dioxaphospliblane. having at least one alkyl radical attached to at least one carbon atom of the dioxaphospholane ring, the other ring carbon atom having 1, to 2 hydrogen atoms attached thereto.

6. As new compounds, 2-(2-chloroacetoxyethylrnercapto)-2-thiono derivatives of l,3,2-dioxaphosphorinanes having at least one alkyl radical attached to at least one carbon atom of the dioxaphosphorinane ring.

7. As newcompounds, 2-(2-benzoyloxyethylmercapto)-2-thiono 1,3,2dioxaphosphorinanes having at least one. alkyl radical attached to at least one carbon atom of thedioxaphosphorinane ring, the other ring carbon atoms having. 1 to 2 hydrogen atoms attached thereto.

8. Process: for: producing heterocyclic phosphorus-containing: esters, which comprises reacting a heteroeyclic phosphorus containing acid of the formula hydrocarbon radicals, and the (CII2)7CH=CHC3H17,

radical.

9. Process for producing heterocyclic phosphorus-containingesters, which' comprises reacting a heterocyclic dithiophosphoric acid of the formula (B 12 0)... PSH

wherein R, R RF, R R and R respectively, designate: a radical of the class consisting of hydrogen and the alkyl groups, and m is" an integer from 0 to 1, with an alkenyl ester ofi' anzalkanoic; acid, at. a temperature within the;

range; hetween abo.ut. e -C. and about 150 C., said alkenyl group having 2; to: 3- carbon atoms.

10. Process; for. producing heterocyclic phosphoruscontaining esters, which comprises reacting a heterocyclic dithiophosphoric acid of the formula wherein R, R R R R and R respectively, designates f a radical of 'the-class consisting of hydrogen and the alkyl groups, and m is an integer from O to 1, with an alkenylesterofa-hal'o-allcanoic acid, at a temperature within the range between about -20 C. and about 150 C., said alkenylgroup having 2 to 3 carbon atoms.

11. Process for producing heterocyclic phosphoruscontaining esters; which comprises reacting a heterocyclic dithiophosphoric'acid of the formula wherein-R, R R R R and R respectively, designates a radical of theclass-consisting of hydrogen and the alkyl groups, and m: is an integer from 0 to 1, with an alkenyl ester of hydrocyanic acid, at a temperature within the range between about --20 C. and. about 150 C., said alkenyl group having 2. to 3 carbon atoms.

wherein R, R R R R and R respectively, designates a radical of the class consisting of'hydrogen and the alkyl groups, and m is an integer from 0 to 1, at a temperature within the range between about 20 C. and about C. 7

References Citedin the file of this patent UNITED STATES PATENTS 2,791,574 Lanham May 7, 1957 

1. AS NEW COMPOUNDS, HETEROCYCLIC PHOSPHORUS-CONTAINING ESTERS HAVING STRUCTURES CORRESPONDING TO THE FORMULA
 8. PROCESS FOR PRODUCING HETEROCYCLIC PHOSPHORUS-CONTAINING ESTERS, WHICH COMPRISES REACTING A HETEROCYCLIC PHOSPHORUS-CONTAINING ACID OF THE FORMULA 